Salivary Glands Module 2

Question 1

what are the several common features of acinus aka secretory endpiece?

Answer 1

comprised of a cluster of acinar cells surrounding a central lumen
there are spaces between the cells- intercellular spaces and the cells are joined by tight junctions
end of acinar cell that faces the lumen contains secretory granules
surrounding acinar cells- myoepithelial cell
entire endpiece surrounded by basal lamina

Question 2

what does the tight junctions and intercellular spaces allow for?

Answer 2

passage of water and small ions but restrict the passage of larger molecules

Question 3

serous cell characteristics

Answer 3

pyramidal shape
rest on basal lamina
short irregular microvilli- inc surface area
exhibit many characteristics of polarized, protein secreting cells- nucleus toward basal aspect of cell, surrounded by protein synthesizing and processing organelle- rER and golgi apparatus
secrete many enzymes and glycoproteins- packaged in secretory granule in apical part of cell where they are released

Question 4

what are one class of proteins serous cells do not secrete?

Answer 4

mucins- left to mucous cells

Question 5

what do ducts have

Answer 5

larger lumen

Question 6

serous acini lumen-

Answer 6

very small

Question 7

serous acini nuclei

Answer 7

clear

Question 8

mucous cell characteristic

Answer 8

more cuboidal to columnar in shape- less pyramidal
oval nuclei pressed toward base
arranged in tubules around a larger central lumen- arranged in acini more elongated and tubular
secrete mucins
mucins cause secretory granules that contain them are pale staining

Question 9

where are the mucous granules?

Answer 9

in apex of cell- several mucous granules apparently merged together- fixation problem

Question 10

mucous vs serous appearance

Answer 10

shapes of endpieces more tubular - only seen in longitudinal cross section
cytoplasm of mucous cells much paler staining than serous cell
nuclei of mucous cell- further basally than serous cell
lumen of mucous larger and more obvious

Question 11

serous demilune

Answer 11

serous cells on top of mucous cells in mixed acinus

due to conventional fixation

Question 12

rapid freezing technique?

Answer 12

mucous and serous side by side
mucous nuclei not compressed
do not change basic function of mixed acinus

Question 13

myoepithelial cells-

Answer 13

specialized epithelial cell with contractile properties
surround acini and intercalated ducts
lie within basal lamina
have multiple processes
one cell surround a bunch of multiple cells of acinus

Question 14

how is myoepithelial cells innervated and what is their function?

Answer 14

neurally innervated

facilitate movement of saliva into ductal system

Question 15

what does acini open into?

Answer 15

intercalated lead to striated and to excretory- open into oral cavity

Question 16

does major salivary glands have all three types of ducts?

Answer 16

yes

Question 17

does minor salivary glands have /all 3 types of ducts

Answer 17

no
intercalated sometimes observed
striated absent
excretory main type

Question 18

intercalated duct

Answer 18

smallest duct
several acini drain into intercalated duct
ducts short
cells: cuboidal with centrally placed nucleus
function: convey saliva and secrete antimicrobial proteins- lysozyme- break down bacteria- lactoferrin- antiviral fungal and bacterial
lumen larger than acini

Question 19

striated duct

Answer 19

longer more active duct
site of reabsorption
converts isotonic to hypotonic fluid- primary to secondary saliva
againast conc gradient- requires atp
also site of secretion of proteins and bicarbonate- vital for buffering of saliva

Question 20

morphology of striated duct

Answer 20

columnar
highly polarized
short microvilli
numerous infoldings o basolateral membrane- striation appearance- large sa for reabsorption
prominent mitochondria

Question 21

pathway for reabsorption

Answer 21

sodium and chloride ions in primary secretions of the lumen get taken up at the apical end of the striated duct cell and transported through the celll to its basal aspect where they pass to capillaries adjacent to the striations at the basal end of the cell

Question 22

excretory duct

Answer 22

carrying saliva to oral cavity

series of connecting ducts becoming progressively wider closer to mouth

Question 23

changes in histo of excretory duct?

Answer 23

single epithelial layer to pseudostratified epithelium, sometimes final part of duct becomes stratified and keratinized (increased strength)

Question 24

excretory duct histo

Answer 24

often located in ct
irregularly shaped lumen
irregularly positioned nuclei- pseudostraitiied. fibroblast surround duct- bc duct often in stroma- ct of the gland where fibroblasts and collagen prominent

Question 25

what are goblet cells?

Answer 25

intermingled with other excretory duct cells and do secrete mucins

Question 26

von ebner’s gland

Answer 26

taste bud bearing
foliate and circumvalate papillae of posterior tongue
pure serous

Question 27

age changes

Answer 27

general loss of parenchyma 30-60%

does not necessarily induce dry mouth- most dry mouth in the elderly drug related

Question 28

what other diseases and conditions influence salivary gland

Answer 28

mumps- viral, parotid gland swelling
sialoliths- stones, submandibular- obstruct secretion cause painful swelling
mucous plugs or trauma- obstruct secretions from minor glands- painful swelling
several virsuses replicate and shed nto saliva- ebv and herpes

Question 29

hyposalivation

Answer 29

severity of symptoms dependent on degree of salivary loss
xerostomia
mucosal changes
enamel erosion
increases caries
difficulty in chewing and swallowing
changes in taste

Question 30

causes of hyposalivation

Answer 30

genetic mutation- rare

medications0 antichlinergic drugs, diuretics, antidepressants, antihistamines, antihypertensives

Question 31

system disease that give rise to dry mouth

Answer 31

prodromal symptom of mumps- xerostomia, sjogren, diabetes

Question 32

iatrogenic cause of hyposalivation

Answer 32

head and neck radiotheapy

Question 33

head and neck radiotherapy

Answer 33

effects rapid and long lasting
initial effect; bc of reduce gland function
later effects- bc of cell death- primarily acinar
newer radiation therapies that more specificially target tumor site can spare salivary function

Question 34

solution to problem?

Answer 34

use either stem cell therapy or genetically modify remaining tissue to restore salivary flow- transform ductal cells

Question 35

hyposalivation treatment

Answer 35

preventative- most
frequent dental eval and prophy due to prevalence of complications
artificial saliva- poor patient compliance
salivary stimulants- sugarless candies and chewing gum
drugs- muscarinis cholernergic agonist- trigger salivary flow but gi side effects prohibitive